package com.fh.util;

import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTVerifier;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.interfaces.Claim;
import com.auth0.jwt.interfaces.DecodedJWT;
import lombok.extern.slf4j.Slf4j;

import java.util.Calendar;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;


@Slf4j
public class JwtTokenUtils {


    /**
     * token秘钥，请勿泄露，请勿随便修改 backups:JKKLJOoadsafa
     */
    public static final String SECRET = "JKKLJOoadsafa";

    /**
     * token 过期时间: 10天
     */
    public static final int calendarField = Calendar.DATE;
    public static final int calendarInterval = 10;

    /**
     * JWT生成Token.<br/>
     * <p>
     * JWT构成: header, payload, signature
     */
    public static String createToken(Integer memberId, String phone) throws Exception {
        Date iatDate = new Date();
        // expire time
        Calendar nowTime = Calendar.getInstance();
        nowTime.add(calendarField, calendarInterval);
        Date expiresDate = nowTime.getTime();

        // header Map
        Map<String, Object> map = new HashMap<>();
        map.put("alg", "HS256");
        map.put("typ", "JWT");

        // build token
        // param backups {iss:Service, aud:APP}
        String token = JWT.create().withHeader(map) // header
                .withClaim("iss", "Service") // payload
                .withClaim("aud", "APP")
                .withClaim("memberId", memberId)
                .withClaim("phone", phone)
                .withIssuedAt(iatDate) // sign time
                .withExpiresAt(expiresDate) // expire time
                .sign(Algorithm.HMAC256(SECRET)); // signature

        return token;
    }


    /**
     * 解密Token
     *
     * @param token
     * @return
     * @throws Exception
     */
    public static Map<String, Claim> verifyToken(String token) {
        DecodedJWT jwt = null;
        try {
            JWTVerifier verifier = JWT.require(Algorithm.HMAC256(SECRET)).build();
            jwt = verifier.verify(token);
        } catch (Exception e) {
            log.info("token转换失败,可能失效,可能被篡改" + token);
            // token 校验失败, 抛出Token验证非法异常
            return null;
        }
        return jwt.getClaims();
    }


    /**
     * 根据Token获取user_id
     *
     * @param token
     * @return user_id
     */
    public static Map<String, Object> getUserInfo(String token) {
        Map<String, Claim> claims = verifyToken(token);

        if (claims == null) {
            return null;
        }
        Map<String, Object> resultMap = new HashMap<>();
        Claim memberIdClaim = claims.get("memberId");
        Claim phoneClaim = claims.get("phone");

        if (null != memberIdClaim) {
            resultMap.put("memberId", memberIdClaim.asInt());
        }
        if (null != memberIdClaim) {
            resultMap.put("phone", phoneClaim.asString());
        }

        return resultMap;
    }
}
